In most cases of light to moderately-deep scratches, you can buff them out right at home. However, if a scratch has made its way to the primer level or even to the bare metal of your car, a professional should address it as soon as possible.
How do you tell if scratches will buff out?
In the automotive industry, there is a RULE of THUMB. If your thumb can't catch the scratch then it can be buffed out easily using Toothpaste as it's only on the clear coat of paint and if not then you need to go out with a car scratch repair kit or repainting because it's way too deep to buff out.
Do buffed out scratches come back?
Re: Will swirls or scratches come back? If the swirls and scratches are removed, they will not come back on their own. If they are simply hidden, they will come back.